Air in CH system

[Tony]

Hello

I have CH problem where the CH stops working due to air entering the system. I can get it going again by bleeding the pump and then it works ok for a couple of days. This problem has got progressively worse and I now need to fix it asap.

Anyone have any ideas what could be causing this?

Thanks

Tony

[Set Square]

Are you sure it's air? It could be hydrogen, resulting from corrosion, unless you have sufficient inhibitor in the system. Next time you bleed a radiator, collect some of this 'air' in an upturned jar, and see whether it burns when you put a match to it. If it does, it's hydrogen - and you need to tackle the corrosion.

If it doesn't, you need to investigate where air is getting in. Does the F&E tank have sufficient water in it - or has the ball valve stuck? Is the system pumping over? Etc.

[Tony]

I'll have to do the check for Hydrogen you suggested and have a look at the expansion tank but I know for sure there's no inhibitor in the system as it was drained down recently by a plumber when the rad in the bathroom was changed.

Is this important and do you have any recommendations for inhibitor?

Cheers

Tony

[Set Square]

Something like this

do the trick.

If you are generating hydrogen, you *definitely* need it.

[Tony]

In-case anyone's interested, I used Fernox Restorer in the system for a week, then refilled with Fernox Inhibitor and now everything works fine.

Thanks for your help.